Manufacture of welded spiral pipe



May 3, 1938.

H. W. FORCE MANUFACTURE OF WELDED SPIRAL PIPE Filed Sept. 25, 1933 Q ShGGtS- SI'IG Bt l INVENTORY BY xwaz M QM.

, a v m MWZZAW/V ATTORNEYS, I

May 3, 1938. H. A- R E' 2,115,925

. MANUFACTURE OF WELDED SPIRAL PIPE Filed Sept. 25, 1953 2 Sheets-Sheet 2 3 INVENTOR, Z2. $4.061 201 1 .1 5 1 A BY 730mm m ATTORNEYS.

Patented May 3, 1938 2,115,925 1 MANUFACTURE or WELDED SPIRAL PIPE HaroldW. Force, Oakland, Calif., assignor, by mesne assignments, to The American Rolling vMill l(illompany, Middletown, Ohio, a corporation of 'o Application September 25, 1933, Serial No. 690,817 7 Claims. (Cl. 78-86) This is a continuation in part of my copending application for Manufacture of welded spiral pipe, Serial Number 445,917, filed April 21st, 1930.

The principal objects of the present invention ment of the several parts herein shown and de-- scribed, without departing from the spirit of the invention as defined in said claims.

Reference should be had to the accompanying 55 d awings in which Fig. 1 is a plan view, partly conventional, and partly diagrammatic, of an apparatus for making spiral pipe embodying oneform ofmy invention.

approximately contiguous and inabutting relation. Because of the inherent inaccuracy in the edges of metal sheets of this character, which sometimes amounts to a perceptible curvature,

the relative positions of said edges when they first are the same as those set forth in the above Fig. 2 is a longitudinal section on the line 22 mentioned application, viz:to provide for the of Fig. 1. rapid formation of a perfect welded helical seam Fig. 3 is a transverse section on the line 3-3 between the adjacent convolutions of a helically 0f Fig.2. wound strip or sheet in the manufacture of so Fig. 4 is a frag y P illustrating called spiral pipe, and to compensate for acci- Other means for maintaining an open seam dur- 10 dental variations in the width of the incoming ng the heat n of the e es t eo sheet or for slight curvature of its edges. Fig. 5 is a transverse section enlarged, on the These objects are attained in a manner generiline 5-5 of Fig. 4. cally similar to that described in said copending 6 i a a e t y tu na Sec on flapplication, viz:-by winding a strip or sheet of lustrating an th r m a s for s n the openlu metal helically to bring the edges of its convolu- Seam and forming the Weldtions into approximately parallel and adjacent Fig. 7 is a broken plan View Showing e relation; then separating said edges or maintainm d fic ti n of h am pr n me nsing a space between them and applying heat Fig. 8 is a broken side elevation of the form thereto from a gas torch or other suitable means, shown in Fig- 7, taken on the line e e f- 20 the separation of the edges causing them to be Figs. 9, 10, 11 and 12 are transverse sections evenly heated throughout the thickness of the taken on the correspond numbered lines metal, by permitting the flame to pass between g- 8- them and reach their under surfaces; and finally In the drawings, the reference numeral 1 desigclosing or filling the space between the heated hates a sheet or strip of metal which is wound edges to form a welded seam, which, on account helically to form a tube or pipe 8. Any suitable of the even heating, can be made with greater guide means indicated as rollers 9 may be emspeed and more perfect results than is possible ployed for guiding the sheet 1 at the proper anunder other conditions. gle to the bending or winding means which is The present invention includes certain means illustrated conventionally as comprising parallel an for opening and maintaining the proper space rollers l0, bearing against the surface of the between the adjacent edges of the helically wound sheet in proper positions to bend it into tubular sheet, disclosed but not claimed in my said co form with its rear edge Ia adjacent its forward pending application, and adds theretoa new modedge bhe tube s o ed d s 01f the ified form of means for the same purpose. It bending rollers l0 endwise, impelled by the com- 35 also includes another novel feature which conbined action of said bending rollers and the guide sists in closing or filling the open seam by forcirollers 9, and the adjacent edges of its helical bly squeezing or pressing the heated edges toscam are heated by a suitable instrumentality ingether in abutting relation to cause them to fuse e ted at a d Su s q y Welded to fo m 40 to form the welded seam, whereas in said 00- a rigid pipe. The end or finished portion of the 40 endi g application the seam is closed and weldp pe is s pp r d a guided y ny i able ed by supplying molten metal thereto from a means, for example, a pair of concave rollers l2. outside source, as for example from a metal w ld It is understood that the axes of the rollers l2 rod. It is to be understood that either method y be ju a laterally for the a purp s of filling or closing and welding the seam may be of shifting the axis of the finished portion of 45 used in carrying out the present invention, or the pipe rel tive to t xi f win in of heeven, if desired, both methods maybe used simulsheet, and for increasing and decreasing the taneously, and moreover, that changes, within sp e between S d ol e sthe scope of the claims hereto appended, may be The angle of feed of the incoming sheet I is made in the form, construction and arrangeso adjusted as to cause its edges la and lb to be 5 meet in the winding of the tube is not constant. This is not troublesome, however, because the subsequent operations are designed fullyto compensate for such inaccuracy in the initial relation between the adjacent edges.

The first operation, after the winding of the sheet into tubular form, consists in spreading its adjacent edges to form an open seam of constant width. Such spreading may be accomplished in a number of ways. It may be done byshifting the guide rollers 12 to offset the axis of the fin- 4 ished portion of the pipe with respect to its axis of winding, as described in my copending application above referred to, or, as illustrated in Fig. 1 herein, the wound tube may be passed over a floating plug l3 whose diameter is such as to cause a slight expansion of said tube, thereby opening the seam to the desired width, as shown at ll. The end portions of the plug ii are preferably tapered, as shown, and it is held against longitudinal movement by a rod I5, whose end is secured to any suitable portion of the frame of the machine (not shown). The plug l3 may or may not rotate upon the rodii.

At approximately the point where the seam ll reaches its maximum spread, its edges are heated by the welding torch ll, illustrated in Figs. 1, 2

' and 3 as a gas torch. At this point the plug I3 is provided with a peripheral groove II. The welding flame, therefore, passes between the separated edges of the sheet and is enabled to heat them evenly throughout their entire thickness.

As the wound tube passes of! the plug I, it iscompressed or squeezed between the guide rollers II, which compression slightly decreases its diameter and closes the hitherto open seam, pressing the heated edges together in abutting relation with sufiicient force to cause them to fuse into a permanent weld, as indicated by the dotted line H. An alternative means for forming the weld is illustrated in Fig. 6 in which an electric welder is indicated at l8 instead of the gas torch of Fig. 1. A metal electrode or weld rod I! is provided from which extra metal is supplied to fill the open seam H, and to form the weld by fusing with the edges of the sheet. In this modification the interior plug I3 is provided with only a small shallow groove 16 so that it may provide a backinl to prevent the molten metal from falling through to the inside of the pipe.

In Figs. 4 and 5 I have shown an alternative means for maintaining the open seam ll. The interior plug IQ of Fig. 1 is dispensed with and a flat guide fin 20 is attached to any convenient portion of the frame of the machine, not shown, in a position to cause it to extend between the adjacent edges of the wound sheet, thereby maintaining the desired space between them. Rollers 2| are carried by the guide fin 2d and bear against the inner and outer surfaces of the edge portions of the wound sheet to maintain said edge portions in horizontal alignment. The welding means, which may be either the gas torch l I and compression rollers ii of Fig. 1 or the electric welder ll of Fig. 6, operates upon the open seam ll immediately behind the guide fin ll.

Another alternative means for spreading and maintaining the open seam during the heating of its edges is illustrated in Figs. 7 to 12 inclusive. in which the sheet 1 is wound by the bending rollers I! about a stationary mandrel 22. Slidably mounted upon said mandrel is a partial sleeve II,

' positioned beneath the incoming portion of the sheet, and secured to the mandrel by slot and bolt connections 24 for longitudinal but not roof metal into tubular form;

- ward end mounted upon said support,

ausms tary movement. The forwa (left hand) end 25 of the partial sleeve 23 is ormed upon a helical line corresponding to the helical seam of the pipe, and bears against the rear edge 1a of the sheet for a portion of its travel before it meets the forward edge lb.

Suitable means, indicated as an adjusting screw ll, are provided for shifting the partial sleeve 23 along the mandrel, so that, by moving said sleeve forwardly (toward the left); its end 25 forces the edge Ia of the sheet away from the rear edge 1b, thereby producing and maintaining the open seam ll, as shown in Figs. 7, 8 and 9. The heating torch is positioned just beyond the end 22' of the mandrel, so that its flame penetrates freely to the inside of the pipe to heat the spaced edges evenly. The compression rollers H, as in the previously described forms, follow closely to squeeze the heated edges together to form the weld l1.

It will be readily appreciated by those skilled in the art that either means described and shown herein for closing the previously opened seam and forming the weld, i. e. either the compression rollers I! or the weld rod IQ (of Fig. 6) may be used with any of the means for initially opening the seam, i. e. the enlarged plug iii of Fig. 1, the guide fin 2| of Figs. 4 and 5, or'the partial sleeve 23 of P18. 8. I claim:

1. An apparatus for making spiral welded pipe comprising means for helically winding 9. sheet of metal into tubular form; a plug within the formed tube, a portion of said plug having a diameter sufiicient to expand said tube by contact .with its inner surface, thereby openingand maintaining a space between the adjacent edges of its convolutions; means for heating said edges while spaced by the expanding action of said plug; and means for forcing said heated edges together to form a welded seam.

2. An apparatus for making spiral welded pipe comprising means for helically winding a sheet a plug within the formed tube, a portion of said plug having a diameter sufiicient to expand said tube by contact with its inner surface, thereby opening and maintaining a space between the adjacent edges of its convolutions, and said plug having a depression in its surface in the region of its greatest diameter over which the spaced edges pass; means for heating said edges evenly throughout their entire thickness while passingover said depression; and means for subsequently forcing said heated edges together to form a welded seam.

3. An apparatus for making spiral welded pipe comprising means for of metal into tubular form; a fixed guide member lying between the adiacent convolutions of the wound sheet to maintain a space between the edges thereof; rollers carried by said guide member and'bearing against the faces of said convolutions adjacent to their edges to maintain said edges in alignment; means for heating said spaced edges; and means for forcing said edges to ether-to form a welded seam.

4. An apparatus for making spiral pipe comprising a fixed support; means for helically winding a sheet of metal into tubular form about said support; a guide member having a helical forsaid forhelically winding a sheet ward end being formed and positioned to bear against the rear edge of the first convolutions of the winding sheet to force it away from the adjacent forward edge of the incoming, sheet,

thereby opening and maintaining a space between said edges; means for heating the spaced edges; and means for subsequently forcing said heated edges together to form a welded seam.

' 5. An apparatus for making spiral welded pipe comprising means for helically winding a sheet of metal into tubular form with adjacent edges in abutting relation, means for creating a space between the adjacent edges of the wound sheet, means for heating said spaced edges, and oppositely disposed concave rollers bearing against the outer surface of the tubular wound sheet after it has passed 'said heating means, said rollers being formed to fit the contour of said tubularly wound sheet and spaced to contract it 'to force its heated edges together to form a welded seam.

6. An apparatus for making spiral welded pipe comprising means for winding a sheet of metal into tubular cylindrical form with adjacent edges in abutting relation, means for creating a space between the adjacent edges of the wound sheet to provide a helical open seam, means for heating said edges while spaced apart, the heating medium passing through the open seam to heat said edges evenlyto welding temperature through the entire thickness of the sheet, and means for applying pressure to the wound tube subsequent to and remote from saidheating means to force said heated edges together with vsuflicient pres- 5 sure to cause them to weld, thereby forming a continuous welded helical seam.

7. An apparatus for making spiral welded pipe comprising means for helically winding a sheet. ofmetal into tubular cylindrical form with adja- 1 cent edges in abutting relation, means for separating the adjacent edges of the wound sheet to provide a helical open seam, means for subsequently forcing said edges together under sufllcient pressure to cause them to weld when heated 15 to welding temperature, and heating means positioned at approximately the point of greatest separation of said edges, the heating medium passing through said open seam to heat said edges evenly to, welding temperature throughout the 20 entire thickness of the sheet, whereby a continuous welded joint is formed by the said edges when they are subsequently forced together.

HAROLD W. FORCE. 

